Rotary air compressor



May 7, 1963 R. F. voGGENTHALx-:R

ROTARY AIR COMPRESSOR Filed Aug. 25. 19Go .INVE'NTOR RALPH VOGGE'NTHLER NRQR ms TTORNEY Unite States arent Y assassin Patented May 7, 1963 hee 3,088,660 ROTARY AIR COMPRESSOR Ralph F. Voggenthaier, Painted Post, N.Y., assignor to ngersoll-Rand Company, New York, NX., a corporation of New Jersey Filed Aug. 23, 1960, Ser. No. 51,370 S Claims. (Cl. 230-207) This invention relates to rotary type compressors and, more particularly, to a compressor having vanes movable in cylinders of the compressor rotor to produce positive displacement Within the cylinders.

in this type of compressor, sealing of the end faces of the rotor is a problem inasmuch as there is very little clearance permissible and end thrust on the rotor necessitates a very finely adjustable thrust bearing.

it is an object of this invention to eliminate thrust by permitting the rotor `to oat freely endwise between the compressor face plates.

Another object of this invention is to provide a compressor having means for preventing transmission of thrust from a drive and/ or a driven shaft to the rotor.

Another object of this invention is to provide a lubricating and cooling system in a compressor that has thrust isolating means for the rotor.

Another object of the invention is to provide a compressor simple to ldesign and to manufacture and having long life.

Other objects and advantages of the invention will be in part obvious and in part pointed out in the following description of a preferred embodiment.

The drawing is a longitudinal section of a vane type air compressor embodying the features of the invention.

Referring to the drawing the compressor has a casing with a cylindrical bore or compressor chamber 12 within which is disposed a rotary element or rotor 14 with longitudinal radial slots or cylinders 16. Varies 18, which may be of a conventional type well known in the art, are disposed in slots 16.

As is usual with such single stage compressors, casing 10 has an inlet passage 20 and a discharge passage 22 preferably diametrically oppoed to each other. The inlet passage 20 is provided with a series of perforations 24 which extend into gouges 26 to extend the period of admission of incoming gas into -bore 12. At discharge passage 22 similar perforations 2S are provided to conduct compressed gas from bore 12.

Casing 10 is provided with heads 30 and 31 to enclose the ends of bore 12 as well as to seal the ends of rotor 14 against leakage. Heads 30 and 31 have end or face plates 32 and 33, respectively, closely tting the end faces of casing 10 as well as the end faces of vanes 18 and rotor 14 with only enough clearance being provided for lubrication and slight temperature expansion. To provide gas ow into and out of the slots or cylinders 16, face plate 32 has radial passages 100 that communicate with the bore 12 through ports 102 adjacent the rotor slots 16 and through ports 98 disposed near or radially outward of the periphery of rotor 14. Face: plate 33 has passages 90, similar to passages 10d, thai correspondingly communicate with bore 12 through ports 92 and 93 that correspond to ports 102 and 98, respec-l tively. Thus, gas from the inlet 20l passes through ports 93 and 98 to respective radial passages 90 and 100 thence escapes through respective ports 92 and 102 toy the bases of vane slots 16 at the inlet side of the compressor. Such ports and passages on the discharge side of the compressor permit escape of gas in the slots 16 below the inwardly moving vanes to the compressor discharge 22.

Rotor 14 is mounted in heads 30 and 31, and is eccentrically disposed in bore 12. At the `driving end shown at the left in the drawing, head 30 includes a cover member 34 with a flange 36 that encircles the adjacent plate v32. Rotor 14 is provided with a cylindrical end 3S that extends through plate 32 and into head 30. Head 30 has a bore 40 within which is disposed an anti-friction bearing 42 for rotor end 38.

Likewise, the opposite end head 31 is provided with a cover member 44 having a bore 46 to receive anti-friction bearing 48- for the cylindrical end 50 of rotor 14 that reads into head 31. The bearings 42 and 48 support rotor 14 which is freely rotatable, and longitudinally slidable to the extent permitted by plates 32 and 33.

The compressor is provided with a drive shaft 52 that extends through plate 32, into member 34, and is carried by suitable thrust and radial bearings 54 disposed in bore 40 for rotation coaxially with rotor 14. Suitable keepers 56 on shaft 52 prevent axial shaft movement with respect to bearings 54. A retainer 58 bolted to the end of member 34 holds bearings 54 in place and also houses a suitable mechanical type seal 60 for shaft 52 that cooperates with a seal plate 62 screwed to retainer 518 and through which the end of shaft 52 projects. Drive shaft 52 has a spline connection with rotor end 38 of rotor 14, and to this end, rotor end 3S is hollow and provided with splines 64 for engaging corresponding splines 66 on shaft 52. Shaft 52 needs no bearing Within rotor 14 inasmuch as those two elements are individually and coaxially supported to rotate together, but the end 68 of shaft 52 may t the bore 70 of rotor 14 to act as a pilot.

At the end opposite drive shaft 52 the compressor is provided with a driven shaft 72 having a piloted Splined connection indicated at 74 with rotor end 50 that extends into member 44. Splined connection of shaft 72 with rotor 14 is entirely similar to that of shaft 52. Shaft 72 is adapted to drive a fan (not shown) or other similar `accessory and, therefore, extends outwardly of the compressor. ln this instance, shaft 72 is adapted to operate a lubricating and cooling oil pump consisting of a gear 76 mounted directly on shaft 72 and a gear 78 mounted on a shaft 80 which is disposed parallel to shaft '72.

Oil discharged by gears 76 and 7S, that provides lubrication and cooling for the compressor, passes into a discharge chamber 82 and thence into a passage 84 in member 444. Since passage 84 communicates with bore 46, there is a restricted oil flow through the bearing 48, through the clearance between rotor end 50 and the opening in plate 33 through which end 50 passes, and into the bore 12. A port 112 connects the discharge chamber 82 to the interior of a retainer 114 to provide oil which lubricates a shaft seal 116 constructed preferably like seal 60, as Well as a bearing 118 that supports shaft 72. Lubricating oil from bearing 48 flows through the `Splined connection '74 of shaft 72 and rotor end 50', a passage in rotor 14, and the splines 64 and 66` to bearings 42 and 54 in head 30. To prevent possible blockage of this oil iiow, the piloted ends of shafts 52 and 72 can be ported as at 53 and 73, respectively. The oil in head 30 flows through bearing 42, through the clearance between the rotor end 318 and the opening in plate 32 through which end 38 passes, and into -bore 12. This oil also flows through bearings 54 to lubricate seal 60. To insure adequate lubrication of the vanes 18 and vane slots :16, face plates 32 and 33 have ports 69 which connect bore 40 to port 102 and bore 46 to port 92, respectively, on only the inlet side of the compressor. Thus, as air enters slots 16 from passages 100 and 90, oil in the respective bearings 42 and 4S flows through ports 69 and 102, and 69 and 92, respectively, to the slots 16 with the incoming gas. To provide additional oil to head 30 and bore 12, cross-over or transverse passages 94 and '96 are provided in casing 10. If only 3. one such passage is required, only passage 96 would be retained. As shown, one `suph cross-over iiow path from bearing 48 in head 31 to head 3@ is provided by a passage 85 in head 3l that is connected to passage 96 by a port 88 in plate of head 3l. -Passage 96 is connected by a port 87 in plate 32 of head 3d to ka series of interconnected passages 1016, 1108 and 11@ which communicate with bore All of head 30 adjacent to the seal 60'. The other or second cross-over llow path is provided by a passage S6 in head 31 that connects passage 84 to cross-over passage 94 through a port 83 in face plate 33 of head 31. Cross-over passage 9d is connected to bore 4t) between bearings Se by a port 67 in face plate 32 of head 30 and a passage 104.

Temperature d-ue Vto compression within the compressor is kept low by providing an oil spray in the compressor and to this end lare provided perforations `120 into that section of the cylinder bore from the cross-over oil passage I96. Likewise for aftercooling purposes perforations 122 may ibe provided Ileading into bore `12 near dis-charge passage 22 Vfrom cross-over passage 94. Lubricating oil thus passing into the compressor lfrom heads 30 and 31, and by way of the spraying perforations 1120 and i122 passes into Vthe discharge line and is removed therefrom for re-use.

Drive shaft S2 is adapted to be provided with a pulley which may lbe conveniently removed 4for connection of that shaft with Ia direct drive. For this purpose, the end of shaft `52 projecting from head 3i) is tapered as at 412dand provided with la coupling flange 126 to which is -fastened by suitable cap screws 128 a pulley `130 of the multiple groove type that extends inwardly toward the compressor so that the pull normally applied thereto will be Asubstantially in line with bearings `54. Removal of cap screws 128 permitsrready remova-l of pulley 130 and connection of flange 126 to la suitable direct drive coupling (not shown).

As described above, it will be noted that rotor `14 mounted on bearings 42 and 48 independent of the shafts 52 and 72, exerts no bending forces in those shafts and is self-centering. Pressures applied thereto at the end faces of the rotor by oil pressure from the pump -gears 76 and 7S have a centering effect which provides end sealing. Similarly, `axial forces that may be exerted on shaft 52 or 72 are not transmitted to rotor 14. Furthermore, a great advantage of lthis construction is that when the slots 16 containing varies 18 wear, the rotor 14 may be reversed end for end, and i-ts .life thus doubled. Likewise, the splined connections of shafts 52 and 72, when reversed, will have double the life of a rotor non-reversible.

Thus, by the above construction are accomplished, among others, the objects hereinbefore set forth.

I claim:

l. A rotary compressor comprising la casing having a bore and an inlet land discharge in communication with the bore, a pair of heads connected to the casing for closing the bore to form a compressor chamber, a rotor eccentrica-lly disposed in the chamber and movable endwise between the heads, said rotor having a central bore and cylindrical ends at the ends of the bore that project into the heads and are Asupported therein for rotational and axial movement, a drive shaft independently supported in one of the heads iand having a connection to the rotor that transmits rotary movement and isolates axial movement, a driven shaft independently supported in the other head yand having a connection to the rotor that transmits rotary movement and isolates axial movement, said heads having passages that are interconnected by the bore in the rotor and provide a flow path for lubricating and cooling oil to the shaft connections and to the supports for the shafts and the rotor, rand the [casing having at least one cross-over passage in communication with the passages in both heads to provide a flow path for oil from one of the heads to the other.

2. The compressor according to claim l, and the casing 4 having a plurality of ports between the cross-over passage and the casing bore to provide :an oil spray in-to the cornpressor chamber.

3. A rotary compressor comprising a casing having a bore and an inlet and discharge in communication with the bore, a pair of heads connected to thecasing for closing the `boreto form la compressor chamber, 4a rotor eccentrioally disposed in the chamber and movable endwise between the heads, said rotor having a central bore and cylindrical ends at the ends of the bore that project into the heads and provide a flow path through the rotor, bearings in the heads for rotatively supporting the rotor ends and for permitting axial movement, a drive shaft independently supported in one 0f heads and having a connection to the rotor that transmits rotary movement and isolates axial movement, -a driven shaft independent-ly supported in the other head `and having a connection to the rotor that Vtransmits rotary movement and isolates axial movement, bearings in the heads for independently sup,- porting the driving and driven shafts, the heads having passages in communica-tion with the flow path through the rotor land providing a llow path `for lubricating and cooling oil to the shaft connections and to the bearings, said casing having atleast one cross-over passage in communication with the passages in the heads to provide a ,flow path -for oil from one of the heads to the other and a pump housed in the head supporting the driven shaft and driven by such shaft to supply the lubricating and cooling oil.

4. The compressor according to claim 3, and lthe casing having a plurality of ports between the cross-over passage and the casing bore to provide an oil spray into the compressor chamber.

5. A rotary compressor comprising a casing having a bore `and an inlet and discharge in communication With the bore, la pair of heads connected to the casing, face plates in the heads for closing the :bore to form a cornpressor chamber, a rotor with -a plurality of spaced radial vane slots disposed eccentrically in the chamber and being movable endwise between the face plates, said face plates having radially disposed passages providing ilow paths between the base of the slots and the inlet and discharge portions of the chamber, vanes in the slots movable radially as the rotor turns, said rotor having a central bore land cylindrical ends at the ends of the bore that project through the -ace plates into the heads to provide a flow path through the rotor, bearings in the heads for rotatably supporting the rotor ends and for permitting axial movement, a drive shaft independently supported in one of the heads 'and having a connection to the rotor that transmits rotary movement and isolates axial movement, a driven shaft independently supported in the other head and having -a connection to the rotor that transmits rotary movement and isolates axial movement, bearings in the heads for independently supporting the drive and driven shafts, passages in the heads in communication with the ilow path through the rotor 4and providing lubricating and cooling oil to the bea-rings and the sha-ft connections, and said face plates having ports connecting the passages in the heads to the radially disposed passages in communication with the inlet side of the chamber to provide oil to the inlet iiow for lubricating the vanes and vane slots.

6. The compressor `according to claim 5, and a pump disposed in the head supporting the driven shaft, and drliven lby such shaft .to supply the lubricating 'and cooling o1 7. The compressor according to claim 5, and the casing having a-t least one cross-over passage in communication with the passages in the heads to provide a flow path from one head to the other for the oil.

8. The compressor according t-o claim 7, and the casing having a plurality of ports between the cross-over passage and the casing bore to provide an oil spray into the compressor chamber.

(References on following page) 5 References Cited in the le of this patent 2,961,151 UNITED STATES PATENTS 2,975,964

2,498,972 Whiteley Feb. 28, 1950 2,862,655 Dickson Dec. 2, `1958 5 853 204 2,937,807 Lorenz May 24, `1960 6 Fobi'an Nov. 22, 1960 Osfnerkamp Mau'. 21, 1961 FOREIGN PATENTS Fmance Nov. 28, 1939 

3. A ROTARY COMPRESSOR COMPRISING A CASING HAVING A BORE AND AN INLET AND DISCHARGE IN COMMUNICATION WITH THE BORE, A PAIR OF HEADS CONNECTED TO THE CASING FOR CLOSING THE BORE TO FORM A COMPRESSOR CHAMBER, A ROTOR ECCENTRICALLY DISPOSED IN THE CHAMBER AND MOVABLE ENDWISE BETWEEN THE HEADS, SAID ROTOR HAVING A CENTRAL BORE AND CYLINDRICAL ENDS AT THE ENDS OF THE BORE THAT PROJECT INTO THE HEADS AND PROVIDE A FLOW PATH THROUGH THE ROTOR, BEARINGS IN THE HEADS FOR ROTATIVELY SUPPORTING THE ROTOR ENDS AND FOR PERMITTING AXIAL MOVEMENT, A DRIVE SHAFT INDEPENDENTLY SUPPORTED IN ONE OF HEADS AND HAVING A CONNECTION TO THE ROTOR THAT TRANSMITS ROTARY MOVEMENT AND ISOLATES AXIAL MOVEMENT, A DRIVEN SHAFT INDEPENDENTLY SUPPORTED IN THE OTHER HEAD AND HAVING A CONNECTION TO THE ROTOR THAT TRANSMITS ROTARY MOVEMENT AND ISOLATES AXIAL MOVEMENT, BEARINGS IN THE HEADS FOR INDEPENDENTLY SUPPORTING THE DRIVING AND DRIVEN SHAFTS, THE HEADS HAVING PASSAGES IN COMMUNICATION WITH THE FLOW PATH THROUGH THE ROTOR AND PROVIDING A FLOW PATH FOR LUBRICATING AND COOLING OIL TO THE SHAFT CONNECTIONS AND TO THE BEARINGS, SAID CASING HAVING AT LEAST ONE CROSS-OVER PASSAGE IN COMMUNICATION WITH THE PASSAGES IN THE HEADS TO PROVIDE A FLOW PATH FOR OIL FROM ONE OF THE HEADS TO THE OTHER AND A PUMP HOUSED IN THE HEAD SUPPORTING THE DRIVEN SHAFT AND DRIVEN BY SUCH SHAFT TO SUPPLY THE LUBRICATING AND COOLING OIL. 